PATCH [5/n]: Prepare x32: PR middle-end/48016: Inconsistency in non-local goto save area

H.J. Lu hjl.tools@gmail.com
Wed Jun 29 15:25:00 GMT 2011


Ping.

On Sat, Jun 25, 2011 at 9:06 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Thu, Jun 16, 2011 at 10:18 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
>> On Thu, Jun 16, 2011 at 12:56 AM, Richard Guenther
>> <richard.guenther@gmail.com> wrote:
>>> On Wed, Jun 15, 2011 at 9:55 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>>>> On Wed, Jun 15, 2011 at 8:16 AM, Michael Matz <matz@suse.de> wrote:
>>>>> Hi,
>>>>>
>>>>> On Wed, 15 Jun 2011, H.J. Lu wrote:
>>>>>
>>>>>> >> +  /* FIXME: update_nonlocal_goto_save_area may pass SA in the wrong mode.  */
>>>>>> >> +  if (GET_MODE (sa) != mode)
>>>>>> >> +    {
>>>>>> >> +      gcc_assert (ptr_mode != Pmode
>>>>>> >> +               && GET_MODE (sa) == ptr_mode
>>>>>> >> +               && mode == Pmode);
>>>>>> >> +      sa = adjust_address (sa, mode, 0);
>>>>>> >> +    }
>>>>>> >
>>>>>> > That may be appropriate for a branch, but trunk shouldn't contain FIXMEs
>>>>>> > that explain how something should be fixed, instead that something should
>>>>>> > be carried out.  I.e. just fix update_nonlocal_goto_save_area.
>>>>>> >
>>>>>>
>>>>>> I don't know update_nonlocal_goto_save_area enough to fix it
>>>>>> without breaking other targets.  This patch is the lest invasive.
>>>>>> Any suggestions how to properly fix it is appreciated.
>>>>>
>>>>> Well, the most obvious variant would be to move the above code right
>>>>> before the call of emit_stack_save in update_nonlocal_goto_save_area
>>>>> (using r_save and STACK_SAVEAREA_MODE (SAVE_NONLOCAL)).  All other callers
>>>>> of emit_stack_save already make sure to pass an object of correct mode, so
>>>>> this one should too.
>>>>>
>>>>> But I think it's better to just produce a correct array_ref from the
>>>>> start.  get_nl_goto_field creates an array_type for the
>>>>> nonlocal_goto_save_area of correct type (ptr_type_node or
>>>>> lang_hooks.types.type_for_mode (Pmode, 1)), and we should use that.
>>>>>
>>>>> So something like this in update_nonlocal_goto_save_area:
>>>>>  t_save = build4 (ARRAY_REF,
>>>>>                   TREE_TYPE (TREE_TYPE (cfun->nonlocal_goto_save_area)),
>>>>>                   cfun->nonlocal_goto_save_area,
>>>>>                   integer_one_node, NULL_TREE, NULL_TREE);
>>>>>
>>>>> instead of the current building of t_save.  Then r_save also should get
>>>>> the correct mode automatically.
>>>>>
>>>>
>>>> Here is the updated patch.  OK for trunk?
>>>
>>> The explow.c change is ok.  For the function.c change I wonder why
>>> convert_memory_address doesn't do the right thing - from it's documentation
>>> it definitely should, so it should be fixed instead of being replaced by
>>> adjust_address with a zero offset.
>>>
>>
>> convert_memory_address may return a pseudo register converted
>> to Pmode.  But here what we want is the same memory address
>> adjusted for Pmode.  I don't think the usage of convert_memory_address
>>
>
> Here is the code in question:
>
>      r_save = convert_memory_address (Pmode, r_save);
>
>      emit_move_insn (r_save, targetm.builtin_setjmp_frame_value ());
>
> R_SAVE must be lvalue.  But return from convert_memory_address
> isn't. I am re-posting my patch here.  OK for trunk?
>
> Thanks.
>
> --
> H.J.
> ---
> 2011-06-15  H.J. Lu  <hongjiu.lu@intel.com>
>
>        PR middle-end/48016
>        * explow.c (update_nonlocal_goto_save_area): Use proper mode
>        for stack save area.
>
>        * function.c (expand_function_start): Properly store frame
>        pointer for non-local goto.
>
> diff --git a/gcc/explow.c b/gcc/explow.c
> index c7d8183..efe6c7e 100644
> --- a/gcc/explow.c
> +++ b/gcc/explow.c
> @@ -1102,7 +1097,9 @@ update_nonlocal_goto_save_area (void)
>      first one is used for the frame pointer save; the rest are sized by
>      STACK_SAVEAREA_MODE.  Create a reference to array index 1, the first
>      of the stack save area slots.  */
> -  t_save = build4 (ARRAY_REF, ptr_type_node, cfun->nonlocal_goto_save_area,
> +  t_save = build4 (ARRAY_REF,
> +                  TREE_TYPE (TREE_TYPE (cfun->nonlocal_goto_save_area)),
> +                  cfun->nonlocal_goto_save_area,
>                   integer_one_node, NULL_TREE, NULL_TREE);
>   r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
>
> diff --git a/gcc/function.c b/gcc/function.c
> index 81c4d39..131bc09 100644
> --- a/gcc/function.c
> +++ b/gcc/function.c
> @@ -4780,7 +4780,7 @@ expand_function_start (tree subr)
>                       cfun->nonlocal_goto_save_area,
>                       integer_zero_node, NULL_TREE, NULL_TREE);
>       r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
> -      r_save = convert_memory_address (Pmode, r_save);
> +      r_save = adjust_address (r_save, Pmode, 0);
>
>       emit_move_insn (r_save, targetm.builtin_setjmp_frame_value ());
>       update_nonlocal_goto_save_area ();
>



-- 
H.J.



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